Roller bit bearing structure



Nov. 17, 1936. R. R. CRUM 2,061,141

ROLLER BIT BEARING STRUCTURE Filed March 18, 1935 )NVENTOR 190/ m E Cram BY $444M ATTORNEY Patenter] Nov. 17, 1936 PATEN r OFFICE, 1 I

I It. Crum, Whittier, Calif., assignor of onefourth to Edwin A. Perkins and three-eighths to Frank W. Brainard, both of Whittier, Calif.

Application March 18; 1935, Serial No. 1 1,651

Thisinvention relates toroller or disc bits, for

rotary well drilling; and more particularly to the mode in which the discs or rollers arerotatably. mounted.

In a prior application, Serial No. 715,504, filed March 14, 1934, for Roller bit,in the name of -Roland vl'tCrum, a bit structure is disclosed,

having rollers or discs supported by the aid of anti-friction bearings. This application is a continuationxin part of the said prior application.

In such roller bits, it is now common to pro-' vide a bit frame or body with a roller support directed generally in a. radial direction with respect to the axis of the body. It is one of the I objects of this invention to make it possible to support the rollers on the bit frame by the aid of anti-friction bearings and in a sturdy man? ner.

In order to ensure against the accidental dropping oif of the roller when a break or other unforeseen occurrence happens, the bearing structureshould be sturdy andreliable. The

breaking oil? of such structures during deep well drilling operations as'in oil well drilling. results in a costly and time consuming fishing op eration. I

Accordingly'it is another object of this invention to provide a bit structure that can be safely and effectively utilized in deep well drilling.

It is still another object of this invention to provide, an anti-friction bearing structure that is simple in structure and easily assembled. I Thisinvention possesses'many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment ,of the invention. For this purpose. thereis shown aform in the drawing accompanying and formingpart of the present specification. This form shall now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting. sense, since the scope of the invention Fig. 3 is an isometric view of certain parts 55 of the anti-friction bearing structure, the parts being in quarter section and shown in separated positions. The bit body appropriate manner to the frame 1. Upon these arms are supported respectivelythe roller;

cutters 4 and 5, having axes 6 and 1 directed downwardly and toward the main axis 8 of the body. i

Intermediate the roller disc cutters 4 and 5 are a pair of diametrically opposite disc cutters,

one of which is shown at 9. These intermediate cutters can be supported on arms such as 10.

Since in the prior application referred to hereinbefore, the particular construction and advantages of this type of bit structure are amply includes-a mm. I having di-" ametrically opposite arms 2 and 3, joined in any described and claimed, further reference therer to is considered unnecessary. It is advisable merely to note that the bit is adapted to be supported on the end of a drill string, and rotated about the axis 8, the power for rotation being obtained vby appropriate connection to a rotary table or the like at the top of the well.

The roller discs 4 and 5 are appropriately supported for rotation about axes 8 and I in a manner clearly disclosed in Figs. 2 and 3. TIhe arm 2 is shown in this instance as made of a casting or forging having an integral pin II. This pin 1 H has a tapered portion I2 ending in an abrupt shoulder l3. The free end ll of the pin it is shown as externally threaded. In the present instance a ball bearing structure I5 is provided adjacent that end of pin H which is closest to the arm 2. This structure serves asathrust bearing and sustains axial forces acting on the cutter 4. The roller bearing structure It is provided adjacent the free end of pin l4, and sustains.

radial forces, acting on the cutter 4. The manner in which these anti-friction structures are formed constitutes the important features of the invention.

In order to form the inner race for ball bearing structure l5. use is made of a pair of annular members i1 and 18. These have internal surfaces, corresponding with the tapered portion 12 of pin II. The plane of contact between members I1 and I8 is perpendicular to the axis 6, and

occurs at the minimum diameter of the quadrant grooves l9 and 20. Quadrant groove I9 is formed in theannular member I 8 and a corresponding groove 20 is formed in the annular member IT. The two of them in cooperation form the inner race for a series of balls forming the ball bearing structure l5.

The outer race of ball bearing structure I5 is provided by an internal semi-circular groove 2| formed in the inner cylindrical surface of the roller disc 4. By virtue of the split inner race, the assembly of the ball bearing parts is facilitated. Thus for example, the balls I! can first be placed inside of the outer race 2|; then the ring I! can be placed in position from the right hand side of the disc 4, and then member is can be placed inside of the disc'4 from the left hand side thereof.

In order to hold the assembled structure in place on the pin l4, use is made of a flanged retaining member 22. This retaining member has a body portion 23 provided with an external cylindrical surface and an internally threaded portion engaging the threads on the portion l4 of pin Ii. Its inner end has a flat surface 24 adapted to abut against the corresponding adjacent fiat surface of the ring it. As member 22 is threaded onto the pin Ii, its flange 25 is arranged to contact with the inner surface of the cutter 4. The abutting surface 24 serves therefore to confine the ball bearing structure against axial movement with respect to the pin H, and holds the ball bearing structure firmly against the abrupt surface I 3.

The member 22 can be turned for tightening purposes by the aid of a pair of diametric depressions or sockets 26 placed in the flange 25, and capable of being engaged by a spanner wrench. However, in order further to ensure against accidental separation of the parts. a cap screw 21 can be provided, passing through an aperture in flange 25 andthreaded into an axial tapped hole 28 in the pin l I.

In order to provide a sturdy and effective antifriction radial bearing structure, use is made of cylindrical roller members i 6 forming the roller bearing. The inner race for these roller members is provided by the external cylindrical surface of member 22. The outer race is formed by the internal cylindrical surface 29 formed on the inside of the roller disc 4. The rollers I 6 are confined against axial movement by the spacing ofthe flange 25 from the annular member to.

The assembly of the roller bearing I6 is readily apparent. After the ball bearing structure is assembled as heretofore described, the rollers i6 can be inserted inside of the cutter 4; and then the flanged member 22 can be placed inside of the rollers l6. The entire structure can now be telescoped over the pin I I, and member 22 turned by a spanner wrench until the surface 24 abuts against the contiguous surface of the ring it.

Of course there is suflicient running clearance between flange 25 and the cutter 4 to permit its members disposed n said pm, and having free rotation.

ings sturdy construction ensures that in actual use of the bit, there is no hkelihood of any binding um movement.

action, even when the forces imposed on the bit are severe. i

I claim: r v 1. A roller cutter having an inner annular air- I face'forn1ing an outer race, a pair of annular members cooperating to form an inner race, rolls ing members-in the race, a pin upon which the annular members are placed, and detachable w means supported on the members in place. 2. A pin, acutter, and means for rotatably der, posed on said tapered surface, the grooves formin said race, a member threaded on pin to hold the annular supporting the cutter on the pin, comprising a series of balls, a series of rollers, means forming an inner race for the balls and telescoped over the pin, and a member forming the inner race for the rollers and detachably supported on the pin and acting to confine the means forming the inner ball race against movement.

3. A pin having a tapered surface as well as a threaded end, a pair of annular members disposed on the tapered surface and having grooves cooperating to form an inner ball race, a roller cutter having an internal groove forming an outer ball race, as well as an inner cylindrical surface axially spaced from said outer ball race, balls in the said race, an internally threaded member threaded on the pin and having an end surface for confining the annular members against axial'movement, said internally threaded member having an external cylindrical surface, forming with the internal cylindrical surface'of the roller cutter, a roller bearing race, and rollers in said race.

4. A pin support having a tapered surface as well as a threaded end, said tapered'surface having its smaller end adjacent the threaded portion, and its larger end adjacent an abrupt shoulder, 9. pair of grooved annular members disposed on said tapered surface, the grooves forming an inner ball race, a roller disc having an internal groove cooperating with the annular members and forming an outer ball race, balls in said race, and a member threaded on the pin and having a surface confining said annular members against axial movement.

' 5. A pin support having a tapered surface as well as a threaded end, said tapered surface having its smaller end adjacent the threaded portion, and its larger end adjacent an abrupt shoulapair of grooved annular members dising an inner ball race, a roller disc having an internal groove cooperating with the annular members and forming an outer ball race, balls the pin and having a surface confining said annular members against axial movement, said roller cutter and said threaded member having respectively internal and external surfaces forming a race for a roller bearing, and rollers in said race, said threaded member having a flange confining said rollers against outward axial movement, one of the annular members having an end surface confining said rollers against inward axial movemerit.

6. A pin having a threaded end, a pair of ansaid race, and an confining the anmovement; as well 'as a flange for confining the roller cutter against 7. 'A'pin having a threaded end, a pair of annular members disposed on said pin, and having ratin'g'to form an inner ball 1868,

a roller cutter having an internal groove forming an outer ball race; balls in said race, an internally threaded member threaded on the pin and having an end surface for confining the annular members against axial movement, said internally threaded member having an external cylindricalsurface.

forming with an internal cylinaoemai drical surface of the roller cutter, a roller bearmg race, and rollers in said race.

8. A pin having a threaded end, means form I threaded member threaded on the pin and having.

an end surface for confining said inner race against axial movement, said internally threaded member having an external surface forming the inner race of a radial bearing, an internal surface on said cutter forming the outer race oi said radial bearing, roller members between said races, there being a coaxial threaded bore in said pin, and a locking member threadedly secured in said bore having a head, said head engaging said internally threaded member whereby said memher is locked in place.

9. A pin having a threaded end, a cutter, and means for rotatably supporting the cutter on the pin comprising a thrust bearing and a radial bearing, means forming an inner race for the thrust bearing and telescoped over the pin, an internally threaded member threaded on the pin having an external surface forming the inner race for said radial bearing and having an end surface for confining the inner race of said thrust bearing against axial movement, there being a coaxial threaded bore in said pin, and locking means threadedly secured in said bore and engaging said threaded member, whereby said member is locked in place.

ROLAND R. CRUM. 

